The present invention relates to the spraying technology and may be used for a fine and substantially uniform spraying of fluid and paste-like materials.
The invention may be used in industries employing spraying technique in production processes, such as for spray drying, surface coating with films, aerosol production and other like industries where spraying is employed.
Known in the art are various apparatus for spraying liquids: centrifugal and pneumatic nozzles, rotary spraying discs and cones. Such spraying apparatus generate a dispersion featuring non-commensurable particles, which negatively effects the conduct of some processes, such as drying. Fine particles dry more rapidly than coarse particles and are overheated in a flow of a heat carrier.
The same disadvantage is characteristic of a known apparatus for spraying in a pulsating flow of gas (U.S. Pat. No. 3,618,655,). This apparatus comprises a drying plant in which the material being dried is sprayed in an exhaust pipe of a pulsation combustion chamber. The patent, however, fails to disclose the method and apparatus for distributing the material in the gas stream.
Known in the art is also an apparatus for spraying fluid and paste-like materials with a pulsating gas flow, wherein the material being sprayed is fed to a stationary perforated nozzle installed in an exhaust pipe of a pulsating gas flow generator. The disadvantage of this apparatus resides in the absence of means for uniformly distributing the material among perforations of the nozzle so that the spraying of the material in space is non-uniform and chaotic. In this apparatus, as in the apparatus according to the aforementioned U.S. patent, there is no way of controlling the frequency and amplitude of the pulsations so as to optimize the spraying process as to dispersity and energy requirements.